Did some quick napkin maths, and the energy required to raise sea temperatures one degree requires the energy of 1 368 000 gigatons of TNT equivalent. In compar

Did some quick napkin maths, and the energy required to raise sea temperatures one degree requires the energy of 1 368 000 gigatons of TNT equivalent. In comparison, Tsar Bomba is estimated 50–58 megatons of TNT, so you'd need quite a lot of these to produce the same effect. According to NOAA, there's 1.335×10^9 km^3 of water in the oceans. This amounts to 1.335×10^21 liters, and with the density of sea water of 1.025kg/L, 1.368×10^21 kg. The heat capacity of water is 4182 J/(kg×K) around room temperature. This means that when the temperature of oceans raise one degree (Celsius/Kelvin), the energy needed is (1.368×10^21 × 4182) J = 5.722544×10^24 J. One gigaton of TNT equivalent releases 4.184×10^18 J of energy, and dividing the above result with this, you get the amount of gigatons required.